An Early Phase 1 interventional study of SGT-53 and hypofractionated radiotherapy with immunotherapy in CNS Malignancies, Medulloblastoma Recurrent and ATRT Recurrent, sponsored by Children's National Research Institute. Recruiting at 1 site in United States. Open to participants aged 3 Years to 21 Years. Per ClinicalTrials.gov, last updated 2026-04-29.
Sponsored by Children's National Research Institute · Early Phase 1, Interventional, and Treatment
This clinical trial is studying a drug called SGT-53 along with radiation and another drug called Nivolumab. It's for children with brain tumors that have come back, gotten worse, or didn't get better with earlier treatments. The main questions it aims to answer are:
What is the right dose of SGT-53 that children can safely receive when it is used with radiation and Nivolumab? This dose will be used in the second phase of the trial.
What side effects are there of SGT-53 when it is used with radiation and Nivolumab?
How does SGT-53 move through the body when given with radiation and Nivolumab?
How much of the SGT-53 drug is found in the tumor tissue? This will be tested in a small group of patients?
Participants will:
For the first treatment cycle:
Get SGT-53 twice per week Get Nivolumab every 2 weeks Receive radiation therapy during week 2
For Cycles 2-6:
Get SGT-53 once per week during even cycles and twice per week during odd cycles Get Nivolumab every 2 weeks For Cycles 7+ Get both SGT-53 and Nivolumab every 2 weeks In the phase 0 part of the study, 4 participants will have genetic testing performed on their tumor tissue after receiving SGT-53. These samples will be compared to another sample taken from the skin.
66 studies on the registry are indexed under Pinealoma; 11 are open to participants now.
This study's planned enrollment of 18 is below the median of 26 across 43 interventional studies indexed under Pinealoma.
Browse Pinealoma studies →Children's National Research Institute is the lead sponsor of 127 studies on the registry; 47 are open to participants now.
Compared within Pinealoma, this study's primary condition as ClinicalTrials.gg classifies it; the registry's first condition term is Central Nervous System Neoplasms. The counts are of registry records indexed under each term, refreshed daily. How we classify →
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Tumor
a. Patients must have a recurrent, progressive, or CNS for which there are not known curative options.
i. Medulloblastoma, ATRT, High grade gliomas, pineoblastomas, embryonal tumors NOS, CNS sarcomas, ependymomas, other high-grade malignancies that failed therapies.
ii. Patients should have received radiation for standard up-front therapy. iii. Patients must have received at least one line of standard of care treatment without limitation to the number of treatments received. b. Evidence of clinical and/or radiological progressive disease as defined by RAPNO criteria.
c. Patients with disease are eligible d. Patients must have available archival (formalin-fixed paraffin embedded) or fresh tumor tissue for correlative studies.
Patient Characteristics a. The first 3 patients will be >7 years old to \<22 years old i. Following initial successful treatment of the first 3 patients: Patients must be ≥3yrs and \<22 years of age.
b. Must have recovered from all surgical interventions prior to the start of the radiation and maintenance phases c. Patients must have a BSA of 0.6m2 or more to be enrolled. 3. Previous treatment
i. At least 3 months from craniospinal radiation therapy, ii. Other substantial bone marrow irradiation ≥6 weeks prior to enrollment, iii. Local palliative XRT (small volume) ≥2 weeks. iv. if progressive disease is documented by radiological evidence of disease in areas not previously radiated, no minimum time required.
e. : Patients who are receiving dexamethasone or other corticosteroids must be on a stable or decreasing dose for at least one (1) week prior to enrollment. There will be a maximum allowable steroid dose of 0.5mg/m2/day dexamethasone equivalents f. Growth factors: Patients must have received their last dose of any short acting growth factor at least one week prior to treatment, for long acting or pegylated growth factors, the last dose must be at least two (2) weeks prior to start of treatment.
4. Neurologic Status
a. Patients should be at their neurological baseline for a minimum of one week prior to enrollment.
5. Performance Status
a. Performance status (KarnofskyPS for >16yrs, or Lansky PS for \<16yrs) assessed within two weeks must be >50.
i. Patients who are unable to walk because of neurologic deficits, but who are up in a wheelchair, will be considered ambulatory for assessing the performance score.
6. Organ Function - Patients must have normal organ and marrow function as defined below:
a serum creatinine based on age/gender as below or a or serum ≥ 70ml/min/1.73m2: Serum Creatinine for age/sex Age Maximum Serum Creatinine (mg/dL) Male Female
6-\<10 years 1 1 10-\<13 years 1.2 1.2 13- \<16 years 1.5 1.4 > 16 years 1.7 1.4 The threshold creatinine values in this table were adapted from the Schwartz formula for estimating GFR (Schwartz et al. J. Peds 106:.522, 1985) utilizing child length and stature data published by the CDC.
7. Pregnancy prevention- all patients of childbearing or child fathering potential must be willing to use an acceptable form of while being treated on this study and at least 5 months after receiving the last study treatment.
8. Pregnancy status: Female patients must not be pregnant or nursing. Female patients of must also have a negative serum pregnancy test at the time of enrollment.
9. - Patient and/or guardian have the ability to understand and the willingness to sign a written informed consent document according to institutional guidelines.
Exclusion Criteria:
1. Low-grade-glioma, craniopharyngioma, and other non-malignant CNS tumors are excluded.
2. Patients with diagnosis of diffuse midline gliomas (DMGs) are excluded. 3. Patients with any unrelated systemic illness (serious infection or significant cardiac, pulmonary, hepatic, or other organ dysfunction) that is likely to interfere with ability to tolerate study therapy or study procedure results.
4. Patients with pre-existing cardiac dysfunction defined as baseline EF of less than 35% 5. Patients with pre-existing pulmonary fibrosis, interstitial lung disease, and clinically significant pulmonary lung disease.
6. Patients who are receiving any other drug therapy 7. Patients who in the opinion of the investigator cannot adhere to protocol requirements 8. Patients with history of diseases that required treatment in the last 2 years are not eligible. Asymptomatic laboratory abnormalities (e.g. ANA, rheumatoid factor, altered thyroid function studies) will not render a patient ineligible in the absence of a diagnosis of an autoimmune disorder. Replacement therapy (e.g. thyroxine, insulin or physiologic replacement therapy) is not considered a form of systemic treatment.
9. Patients who have received a within 30 days of start of study treatment are not eligible.
10. Patients with known /AIDS or acute/chronic or C are excluded.
11. Patients who are prohibited from receiving radiation therapy (reached maximum lifetime dose) are not eligible.
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Relapsed: the illness came back after treatment had worked. Refractory: it did not respond to treatment, or stopped responding while still on it.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
A line of therapy is one course of treatment, which may combine several drugs. First-line is the first course given; second-line follows when that stops working or is not tolerated.
“Two prior lines” means two courses that count separately under the study’s rules — not simply two drugs. Ask the study team if you are unsure how yours are counted.
Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
The number of neutrophils, white blood cells that help fight infection, in a given amount of blood. Too few raises the risk of infection.
It is a count, not a percentage of the white cells. Limits are written in units that mean the same: ≥ 1.5 × 10⁹/L is ≥ 1,500 per mm³ (µL). Each lab has its own reference range.
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
The share of blood the heart’s main pumping chamber (the left ventricle) pushes out with each beat, measured by an echocardiogram (heart ultrasound) or a MUGA scan. About 50–70% is normal.
How quickly the kidneys clear creatinine, a waste product, from the blood. A study may estimate it from a blood test with age, weight and sex (often by the Cockcroft–Gault formula), or measure it using blood and urine collected over a set time. Given in mL/min; higher is better.
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Able to have children. For women this usually means from the first period until menopause, unless permanently unable to through surgery; for men, unless permanently sterile. Read who the line is about — participants, women, men, or their partners.
Criteria about it usually ask for contraception during the study and for a time after it.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
Vaccines made with a weakened form of the germ, such as measles–mumps–rubella (MMR), chickenpox and yellow fever. They can be risky when the immune system is weakened. Flu injections are not live; the nasal flu spray is.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Relapsed and refractory
Relapsed: the illness came back after treatment had worked. Refractory: it did not respond to treatment, or stopped responding while still on it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Line of therapy
A line of therapy is one course of treatment, which may combine several drugs. First-line is the first course given; second-line follows when that stops working or is not tolerated.
“Two prior lines” means two courses that count separately under the study’s rules — not simply two drugs. Ask the study team if you are unsure how yours are counted.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Metastases
Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Absolute neutrophil count (ANC)
The number of neutrophils, white blood cells that help fight infection, in a given amount of blood. Too few raises the risk of infection.
It is a count, not a percentage of the white cells. Limits are written in units that mean the same: ≥ 1.5 × 10⁹/L is ≥ 1,500 per mm³ (µL). Each lab has its own reference range.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Platelets
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hemoglobin (Hb)
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Bilirubin
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ULN (upper limit of normal)
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ALT and AST (liver enzymes)
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
LVEF (left ventricular ejection fraction)
The share of blood the heart’s main pumping chamber (the left ventricle) pushes out with each beat, measured by an echocardiogram (heart ultrasound) or a MUGA scan. About 50–70% is normal.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Creatinine clearance (CrCl)
How quickly the kidneys clear creatinine, a waste product, from the blood. A study may estimate it from a blood test with age, weight and sex (often by the Cockcroft–Gault formula), or measure it using blood and urine collected over a set time. Given in mL/min; higher is better.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
GFR and eGFR (kidney filtering)
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Reproductive potential
Able to have children. For women this usually means from the first period until menopause, unless permanently unable to through surgery; for men, unless permanently sterile. Read who the line is about — participants, women, men, or their partners.
Criteria about it usually ask for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Autoimmune disease
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Live vaccines
Vaccines made with a weakened form of the germ, such as measles–mumps–rubella (MMR), chickenpox and yellow fever. They can be risky when the immune system is weakened. Flu injections are not live; the nasal flu spray is.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis B tests
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Patients with recurrent, progressive, or refractory CNS malignancies receiving SGT-53, Nivolumab, and radiation.
Drug: SGT-53 · Radiation: hypofractionated radiotherapy with immunotherapy · Drug: Nivolumab
SGT-53 is a novel cationic liposome encapsulating a normal human wild type TP53 cDNA sequence in a plasmid backbone. The liposome is decorated on its surface with an anti- transferrin receptor (TfR) single chain antibody fragment (scFv) that is designed to target cancer cells through the binding of the TfRscFv to the transferrin receptor. This complex has been shown to efficiently and specifically deliver the TP53 complementary DNA (cDNA) to the tumor cells via receptor-mediated endocytosis of the cationic liposomal complex. Introduction of the TP53 cDNA sequence restores wild-type p53 (wtp53) function in the apoptotic pathway.
Re-irradiation has rapidly grown into a primary consideration in the context of recurrent pediatric CNS malignancies. While not thought to be curative by itself, it has often resulted in temporary symptomatic improvement as well as occasional radiographic regression or stabilization, although as with any irradiation, may also cause some adverse events.
Given the poor prognosis for children with recurrent CNS malignancies and the importance of p53 function in these tumors, we propose a pilot study of SGT-53 in combination with re-irradiation and checkpoint inhibition followed by maintenance therapy with SGT-53 in combination with nivolumab to evaluate the safety, feasibility and preliminary efficacy. SGT-53 will be added to a salvage regimen utilized in patients with recurrent tumors of re- irradiation and nivolumab followed by combination therapy with SGT-53 and nivolumab.
Frequency and type of toxicity deemed at least probably related to SGT-53
Time frame: From enrollment to 3 years from end of treatment.
Plan to share: No
No publications or documents are linked to this record.
Started Dec 2025 (actual). Primary completion is estimated for May 2028, 28 months after the start.
How these figures are worked out, and which studies are left out of them.
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
Contact study teamGet an email when the registry record changes — status, dates, results — or when someone posts here.
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